The New Illustrated Science and Invention Encyclopedia, © 1987, 1989 by Marshall Cavendish Limited has articles on Plumbing (pp. 1989-1992), Pipelines (pp. 1949-1950), and Drainage (pp. 743-746) which give a good background, with illustrations, concerning how drainage systems are set up and how they work and also describe the components of a working drainage system.
Most buildings have a minimum of at least two different types of drainage systems; a storm drainage system and a sanitary, also known as the sewage, drain system. There are certain facilities (and/or buildings within that facility) that have a third drainage system. This third drainage system drains process waters into onsite holding tanks where the process water is treated before it is discharged off of the facility property or it is hauled away as waste that is to be dealt with outside the municipal sewage treatment system.
The storm drainage system is designed to convey rainwater and other forms of precipitation. Water collected from such precipitation is water in its purest form. This water should contain no contaminants. Because of this, storm drainage water can be discharged (untreated) into streams, rivers, lakes or the ground (water disposal via percolation). The storm water system collects water from roof drains and some drains outside the building which collect water runoff from parking lots, sidewalks, lawns, etc. Storm drains convey water into a storm manhole and other drains which are typically routed to natural bodies of water or to the ground. Storm drains are not typically routed to the sewer system and from there to the sewage treatment plant because, being natural precipitation, the material in a storm drain is not considered “contaminated” such that it needs treatment. Furthermore, the volume of storm water is such that if all the rainwater collected was routed to the sewage treatment system, the sewage treatment system would probably be overwhelmed and in order to prevent flooding, untreated sewage would have to be released. This release of untreated sewage is undesirable from an environmental point of view as well as from a legal point of view. It is undesirable from an environmental point of view as raw sewage is not good for any natural ecosystem. It is undesirable from a legal point of view as there are specific laws which prohibit such actions from taking place.
In contrast to storm drainage systems, sanitary drains are designed to drain material into a sewage treatment system and from there the material in the sewage treatment system is conveyed to the sewage treatment plant for treatment.
Problems occur when storm drains are mistakenly cross-connected to sanitary piping. The most serious difficulty occurs whenever heavy amounts of precipitation happen during a relatively short amount of time leading to an excess amount of water being forced through cross-connections into the sanitary piping, where the excess water ends up in the sewage treatment system. This leads to the undesirable situation where the sewage treatment plant has to discharge untreated sewage in order to avoid having their system become overwhelmed with excess water. This discharge of untreated sewage usually puts the sewage treatment plant out of compliance with local, state and Federal water quality laws and regulations.
Problems also occur when sanitary drains are mistakenly cross-connected to storm piping. There is nothing good about the prospect of having untreated sewage present in drains designed to convey only rain water or melted snow. When sewage is present is the storm water system it is considered a “release of untreated sewage” into the environment. This release of untreated sewage is undesirable from an environmental point of view as well as from a legal point of view. It is undesirable from an environmental point of view as raw sewage reeks havoc on the ecosystem downstream. It is undesirable from a legal point of view as there are specific laws that prohibit discharge of untreated sewage and provide for legal sanctions against the building owners as being responsible for causing the release.
Cross-connections of storm drains into sanitary drainage systems and cross-connections of sanitary drains into storm drainage systems are a fact of life in modern society. Finding these cross-connections and fixing them is a responsibility of property owners. Another reality is that the current building owners are not always the same as the people who owned the building when it was built and the plumbing installed. Therefore the current building owners are not always in the best position to understand how the plumbing in the building was installed in the first place.
It is understood that it is standard procedure in designing the plumbing in a new building or even working on the plumbing in an existing building to have blueprints showing each and every pipe and each and every drainage line and where it is supposed to drain. However, it is often true that the paperwork showing where the drains are and where they drain to, does not always match the reality of where the drains are and where they drain. Therefore, methods of tracing drains to determine where material in a drain ends up are often needed to be used to determine where the existing drains are draining.
Current known methods of tracing drains to find out where the material in the drain drains to include a method known as the “Hot Water” method. Because storm water is normally cool (from about 55° F. to about 90° F.), hot water (water at a temperature greater than 100° F.) can be added to each floor drain at a continuous rate. This hot water can then be “looked for” at a storm water manhole by using a remote thermometer to register the actual temperature of the water, noting any sudden increase in the temperature of the water. The advantage of this method is that it is very non-expensive.
The disadvantage of this “Hot Water” method is that it is not very conclusive. If there were only one “cross-connected” drain in a building (and this was known beforehand) this method might work adequately. However, the “Hot Water” method cannot conclusively prove that any one drain was bad because there could be other reasons why the temperature of the water might be elevated. For example, if a sink, which just happened to have hot water running, were to be plumbed to the storm water drain, and if that sink were running during the time another drain was being tested, this would skew the results.
Other known current methods to determine where drains drain to, require the use of visible dyes, other types of dyes, and/or radioactive materials that are detectable either by sight or by the use of an analytical instrument such as, but not limited to, a Geiger counter. In the following table, the use listed for each dye is one example of a suitable use for the visible dye, other types of dye, and/or radioactive materials.
TABLESubstanceUse (1) Brilliant Blue dyefield irrigation tracing (2) Bromidefield irrigation tracing (3) Bromidetile drains for fields (4) Chloridegroundwater, subsurface drains (5) Deuterium isotopestorm sewers* (6) Radionuclidessewer discharge** (7) O18 isotopegroundwater*** (8) Lithium chloridestreams/mine drainage (9) Fluorescent tracerssewage discharge into seawater****,hydrological studies of aquifers,streams, rivers, etc.(10) Metal ions (e.g., lithium)hydrological studies of aquifers,streams, rivers, etc.(11) Bacteriahydrological studies of aquifers,streams, rivers, etc.*as described in “Urban Stormwater Tracing with the Naturally Occurring Deuterium Isotope”, by Sidle et al., Water Environ. Res. 71(6), pp. 1251-1256 © 1999. **as described in “Sedimentation Basin Investigation Using Radiotracers” by Chmielewski et al, Institute of Nuclear Chemistry and Technology, Warsaw, Poland, 15, 79, pp. 481-487, © 2001. ***as described in “Infiltration and Hydraulic Connections from the Niagara River to a Fractured-Dolomite Aquifer in Niagara Falls, New York”, by Yager et al., J. Hydrol. (Amsterdam), 206(1-2), pp. 84-97, © 1998. ****as described in “Tracer Techniques to Evaluate the Dilution Performance of Sewage Submarine Outfall”, by Roldao et al, Water Pollution IV: Modell., Meas. Predict., Int. Conf., 4th , pp. 185-194 (1997). Materials indicated above are available from many sources, including Norlab Inc., P.O. Box 380, Amherst, Ohio 44001 USA (telephone no. 1-800-247-9422).
The currently known visible dyes, other types of dyes and radioactive tracer materials require either visible review of the material in the drain, leading to labor-intensive and sometimes dangerous positioning of workers in difficult-to-reach locations (such as being face down in the middle of a street looking into a manhole with a flashlight) in order to look for visible dye, or the use of analytical devices, or the use of radioactive materials and Geiger counters, which are not always desirable to use around people and animals.
Furthermore, it is usually never desirable to use a visible dye in circumstances where the change in color of the water can be noticed and commented on by the general public.
The article, “Practical Applications of Tracers—Beyond Product Monitoring, by John E. Hoots, Presented at the 1990 Cooling Tower Institute Annual Meeting in Houston, Tex. on Feb. 5-7, 1990, describes the addition of very low concentrations of a chemical tracer to cooling water systems in order to be able to quantify previously unaccounted blowdown, leakage, time of travel of cooling water to nearby waterways, and out-of-specification operating conditions.
U.S. Pat. No. 5,304,800, issued Apr. 19, 1994 to Hoots et al., describes and claims a process for detecting leakage from a process fluid to a temperature-conditioning fluid in an industrial process using a “tracer chemical”.
It would be desirable to have a method of determining where drains lead that offers an alternative to the labor-intensive use of visible dyes or of radioactive materials.